Novel THTPBA/PEG-derived highly branched polyurethane scaffolds with improved mechanical property and biocompatibility

Abstract

Highly branched polyurethane (PU) scaffolds that match mechanical properties are the preferred tissue engineering materials, which is composed of a multi-hydroxyl-terminated poly(butadiene-co-acrylonitrile) (THTPBA) prepolymer and poly(ethylene glycol) (PEG) via 1,6-hexamethylene diisocyanate as anchor molecule. This combination is anticipated to influence or alter hydrophilicity or hydrophobicity, degradation and haemocompatibility of the PEG-derived PUs. Hence, the surface properties, degradability, mechanical and biomedical properties of the PUs were scrutinized and assessed by FTIR, contact angles, gravimetry, stress-strain measurement and haemolysis, platelet adhesion as well as methyl tretrazolium (MTT) assays. The experimental results indicated that the incorporation of THTPBA can mediate the degradation rate, which took place at the urethane or ester bonds in polymer chains. The haemolytic activity, platelet activation, and MTT investigations elicited that the component ratios of THTPBA to PEG had important influence on biomedical properties, including in vitro blood compatibility, cytotoxicity, and cell cycle or apoptosis of the PU scaffolds. The tensile stress-strain investigations showed that the highly branched architecture offered high elastic modulus and mechanical strength. The novel PU scaffolds with highly branched architecture exhibited improved mechanical properties and biocompatibility as well as low toxicity by regulating proper component ratios, and are expected to be employed in tissue engineering, or as potential candidates for other blood-contacting applications. Copyright © 2011 John Wiley & Sons, Ltd.